1. Exploring LynxOS By
How-Shen Chang

2. What is LynxOS? Hard real-time operating system (RTOS) UNIX-compatible
Full POSIX conformance (Portable Operating System Interface)—assures code portability between systems
Multiprocessing
Multithreaded

3. Why LynxOS is RTOS? Designed for absolute determinism
Supports multiple applications with multiple interrupting devices
Usually used on information of sensitive nature

4. Hardware characteristics
Processor support:
Motorola: PowerPC (PPC 601, 603, 604), PowerPC G3 (PPC 75x), PowerPC G4 (PPC 7400,7410,74xx) with Altivec Support, PowerPC IBM 405,440.
Intel: x86(IA-32) Architecture (and compatible).
MIPS
Xscale
ARM9

5. Kernel features Multitasking and multithreaded RTOS
Complete MMU based protected address spaces for tasks
Four scheduling policies (FIFO, Priority Quantum, Round-Robin, Non-preemptive)
Configurable time quantum for priority levels
Configurable tick timer resolution

6. Process management Uses a RT Global Scheduler
implements priority inheritance and priority tracking
Applies a uniform global priorities management
Kernel threads may utilize 1/2 priority steps

7. Scheduling policy SCHED_FIFO (first-in, first-out)
SCHED_RR (round robin)
SCHED_OTHER (Priority based quantum )

8. Memory management
Conventional UNIX protections exist between application threads of different processes
exploits very well hardware memory management unit (MMU) from processor

9. MMU design

10. Networking support
Supported protocols: TCP, UDP, ICMP, IGMP, ARP, RARP, DHCP, NAT, RPC, NTPv3
Network facilities supported are: DHCP, NTP, XNTP, OpenSSL, NFS, Samba
Network device support: Gigabit Ethernet, 100baseT interfaces

11. Successful stories
USPS has counted on Scio system and LynxOS to sort the country’s mail for more than 10 years
ICI’s IDM (improved data modem) used by U.S Army and Air Force to communicate each other

13. Conclusion
LynxOS is the superior foundation for sophisticated real-time systems
Open API
Full POSIX conformance
True Linux compatibility